Could not resist posting on this epic thread! I'm fairly new to reddit.
This is a true story, very creepy/scary and not paranormal. The cops got
involved ha. It happened to a friend, I know the place really well so I
feel I can give a good retelling of it.

So we all live around this park in Michigan that just has paved paths
going through a prairie type of woodland with many varying but mostly
thin Michigan trees thickly and thinly rowed along it. A great dog
walking route which ends at a dam outlet which is also a decent spot for
fishing. One summer the 5 of us or so, probably rode our bikes up and
down and past that trail every day, day and night. It was practically an
ear shot from our friends house. He had the no rules place with an
awesome view overlooking the Huron river. We felt safe, we felt like we
owned that area. It was always relaxing and never eventful, with the
exception of more than a few bike races. Off of this trail was another
trail. Only this was a boardwalk that mazes through a flood plane. It
was beautiful and once you entered you felt encapsulated in this richly
scented miniature lush forest. Needless to say we used to tear ass
through there on bikes, kind of risky because many of the turns were
awkward and slippery. The boardwalk makes two loops, offering a short
walk or a longer one. The latter had a dead end that has a roofed bench
area resembling a sort of shanty but open. Someone scribbled "The Crib"
on the wall and as silly as it was that became it's name. "Hey guys,
wanna ride out to the crib? Let's take this beer out to the crib." Ahh
those were good times...

Anyway, it had been a few years since we gallivanted around there, but
on many occasion one of us will have just come from walking through
there. We all found the place to be a nice memory and very peaceful. One
night, my friend found himself walking the board walk, no big deal I
think he just left our 'no rules' friend's place and decided to go for a
walk before heading home. Knowing the boardwalk trail blindfolded he had
no issue navigating the dark forest. Not much moonlight creeps through
the many canopies, still an enchanting place nonetheless. He stops at
'the crib', decides it's time to pack up and puts his backpack on
heading out. Well as he reaches the end of the one-way leading from the
crib connecting to the loop he hears footsteps on the boardwalk 20 ft or
so behind him. His eyes were fairly adjusted but still it was not easy
to make out an image where the sound was. He stops dead still, listening
to be sure he isn't imagining it. Through the silence he hears the steps
continue, only now getting closer to him. At this point he decides to
call out, "Hello?" he says concerned but calmly. No answer though the
footsteps stop for a moment then continue. "Fuck that." He thinks to
himself and begins walking the trail away from the footsteps.

He made sure not to run but kept walking, only a little quicker. The
trail winds a bit creating blind corners and through the curves he can
hear the footsteps still approaching but never quite right behind him.
He can't see through the foliage and physical confrontation was not a
plan, this was scary. He stops again, knowing there is someone nearby
and now confronts it verbally. "What do you want?! Look, I don't know
who you are but you better stop following me or I'm going to call the
police!" The footsteps continue, my friend won't give him or her or
whatever a chance to get too close. He power walks ahead wishing he
wasn't alone in the dark woods with somebody, apparently ignoring him,
apparently following him. At one point in the trail it crosses a large
creek that has a beautiful stone bridge that you walk under, it holds up
railroad tracks that pass over. My friend quickly thinks to take the
path we sometimes use to skip the trail and take the tracks back to our
nearby friend's place. 20 ft or so ahead, he quickly makes a move up the
hill to the top of the bridge and makes it to the tracks.

At this point he calls 911 and starts explaining what's happening, that
there is someone following him, creeping him out and not responding to
anything he says. It's 150 yards or so to the dam and the edge of the
park, but the police tell him a car is very nearby and is heading to
meet him. My friend explains he may have lost the person but as soon as
he thinks he can relax a bit, a guy comes ambling up the hill, awkwardly
catching his balance as he sees my friend and continues his medium gate
towards him. It's a guy in a hoody with the hood up, head slightly down,
walking abnormally slow and calculated. Bad vibes oozing off this guy,
my friend starts to run. Just as his feet crash on the rocks laid around
the tracks he hears the same noises coming from behind. The guy began
chasing my friend. Running full speed at him, arms bent but no swing at
the elbow, he looked like T-1000 running. My friend said he about shit
himself, but no sooner he sees a squad car pull up in the parking lot
straight ahead about 70 yards away. My friend waves his cell phone at
the cop, who quickly jumps out and jogs towards my friend, seeing the
guy chasing behind. My friend still running, is told to stop and just as
the cop shouts this, the guy goes back to his odd medium gate. After my
friend affirms it's he who called, the cop walks past him to confront
the guy. He tells the guy to stop, gun drawn. The guy DOESN'T STOP. He
just keeps walking towards the cop at this point, no hesitation at all.
Lucky for this guy though, the cop was a badass and decided not to kill
him right then (IMO). The cop bravely walks up and just grabs the guy
who at this point we find out is a pretty young scrawny kid, maybe mid
20s, probably younger. The cop questions him as he walks with the psycho
back to his car, the guy never answers a single question. No name given,
no answers, no reasoning. It was like he didn't know what he was doing
before and doesn't know what he's doing now or why he's there. His only
compliance was physical, nonresistance.

Never got a follow up except that the guy was busted for drugs a good
number of times in the past and is now doing time for warrants. I always
tell my friend I would have run up and socked the little asshole,
especially after finding out he wasn't a bug guy. But... I try to
honestly place myself there and not only did he do the right thing I'm
not sure I would have done better, forget confronting a creepy person in
the dark!

Edit: Sorry it's so long :/

TL;DR: Friend goes for a night walk through a wooded park, gets followed
by a silent menace. Cops are called, guy gets arrested, friend still
gets shook up when asked about it.